This invention relates generally to new and useful improvements in compressive shrinking of fabrics and particularly seeks to provide a novel method for high speed compressive shrinking employing a selectively variable wrap device in conjunction with a rubber belt unit.
Methods and machines for accomplishing compressive shrinking have been developed extensively and are exemplified in U.S. Pat. Nos. 2,021,975 and 2,146,694 where essentially the same action takes place wherein the constraining belt is of thick rubber and the moisture imparted by a water spray device is prevented from escaping during the shrinking action and the maximum speed is around 110 yards per minute and light fabrics and 40-45 yards per minute on heavier fabrics.
There are problems which develop as a result of trying to operate the apparatus of the prior art above speeds of 110 yards per minute, one of the most serious problems being skips or belt vibrations due to the centrifugal force which is created by the mass of the belt following a curved path. When these vibrations occur, they cause the rubber belt to lose contact with the heated drum and those sections of the fabric in that area are not compressively shrunk to the same degree as the balance of the fabric.
It is the purpose of the present invention to obviate the foregoing difficulties previously encountered in operating compressive shrinking apparatus of the prior art at high speeds.